Systems and methods for delivering and deploying an artificial heart valve within the mitral annulus

ABSTRACT

The present disclosure describes devices, systems, and methods for loading, delivering, positioning, and deploying an artificial heart valve device at the mitral annulus. A delivery system includes a delivery member coupled to a handle assembly and extending distally from the handle assembly. The valve device is attached at the distal end of the delivery member, and is constrained within a valve cover of an outer sheath. A delivery catheter is configured to advance the valve relative to the outer sheath, and a suture catheter includes sutures/tethers which maintain proximal tension on the valve prior to deployment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to: U.S. ProvisionalPatent Application Ser. No. 62/404,511, filed Oct. 5, 2016 and titled“Systems and Methods for Loading and Deploying an Intravascular Device”;U.S. Provisional Patent Application Ser. No. 62/430,149, filed on Dec.5, 2016 and titled “Systems and Methods for Loading and Deploying anIntravascular Device”; U.S. Provisional Patent Application Ser. No.62/436,922, filed Dec. 20, 2016 and titled “Systems and Methods forLoading and Deploying an Intravascular Device”; and U.S. ProvisionalPatent Application Ser. No. 62/462,776, filed on Feb. 23, 2017 andtitled “Systems and Methods for Loading and Deploying an IntravascularDevice,” the disclosures of which are incorporated herein by referencesin their entireties.

BACKGROUND

1. Field of the Invention

The present disclosure generally relates to devices, systems, andmethods for loading a replacement heart valve into a delivery system,delivering the replacement heart valve to the targeted anatomy withinthe heart, and deploying the replacement heart valve at the targetedlocation.

2. The Relevant Technology

Intravascular medical procedures allow the performance of therapeutictreatments in a variety of locations within a patient's body whilerequiring only relatively small access incisions. An intravascularprocedure may, for example, eliminate the need for open-heart surgery,reducing risks, costs, and time associated with an open-heart procedure.The intravascular procedure also enables faster recovery times withlower associated costs and risks of complication. An example of anintravascular procedure that significantly reduces procedure andrecovery time and cost over conventional open surgery is a heart valvereplacement or repair procedure. An artificial valve is guided to theheart through the patient's vasculature. For example, a catheter isinserted into the patient's vasculature and directed to the inferiorvena cava. The catheter is then urged through the inferior vena cavatoward the heart by applying force longitudinally to the catheter. Uponentering the heart from the inferior vena cava, the catheter enters theright atrium. The distal end of the catheter may be deflected by one ormore deflecting mechanisms, which can be achieved by tension cable, orother mechanisms positioned inside the catheter. Precise control of thedistal end of the catheter allows for more reliable and fasterpositioning of a medical device and/or implant and other improvements inthe procedures.

An intravascularly delivered device needs to be placed precisely toensure a correct positioning of the medical device, which is essentialfor its functionality, as the device may be difficult to repositionafter the device is fully deployed from the delivery system.Additionally, the ability to recapture a partially deployed device isdesirable in the event that the distal end of the catheter movesrelative to the target location and compromises the precise positioningof the device.

Implanting a replacement heart valve through an intravascular approachinvolves several challenges. Replacement heart valve devices typicallymust be much larger and more complex than other interventional devicessuch as valve clips or annuloplasty devices. This makes loading,delivery, and deployment of the heart valve difficult. Further,replacement heart valves cannot typically be pre-loaded into theassociated delivery system during manufacture, and must be loaded justprior to the implantation procedure. Artificial valves are typicallystored in a glutaraldehyde solution in a storage container duringstorage and shipment, until the valve is attached to the delivery systemjust prior to the procedure. What is needed is a delivery system thatcan load a replacement heart valve, deliver the heart valveintravascularly to the targeted cardiac valve, properly position andorient the valve, and deploy the valve at the targeted cardiac anatomy.

BRIEF SUMMARY

The present disclosure describes devices, systems, and methods forloading a replacement heart valve device into a delivery system,intravascularly delivering the replacement heart valve device to atargeted cardiac valve using the delivery system, and deploying thereplacement heart valve device at the cardiac valve.

In one embodiment, a delivery system for intravascularly delivering areplacement heart valve to a targeted cardiac valve includes a handleassembly, an elongated delivery member, and an expandable replacementheart valve device. The delivery member has a proximal end and a distalend. The proximal end of the delivery member is coupled to the handleassembly and the delivery member extends distally from the handleassembly to its distal end. The delivery member is configured todetachably couple to the expandable replacement heart valve at thedistal end. The delivery member also includes an outer sheath having avalve cover configured to constrain the valve in a compressedconfiguration, a steering component configured to curve/steer thedelivery member to enable intravascular delivery of the delivery memberto the targeted cardiac valve, a delivery catheter configured tolongitudinally translate the valve relative to the outer sheath duringdeployment, and a suture catheter having one or more tethers configuredto detachably couple to a proximal section of the valve, the suturecatheter being longitudinally translatable relative to the deliverycatheter to enable adjustment of tension in the one or more tethers.

In some embodiments, the delivery catheter includes a compression coilat least at a distal section. The delivery catheter may include a distalcap (also referred to as a can) configured in size and shape toconstrain a proximal section of the valve when the valve is held in thecompressed configuration, the distal cap thereby relieving expansionpressure against an inner surface of the valve cover.

In some embodiments, the suture catheter includes a connecting ringdetachably connected to a distal end of the suture catheter. A pluralityof tethers may be coupled to the connecting ring and extend distallyfrom the connecting ring.

Other embodiments may include a pre-assembled heart valve assembly, inwhich a plurality of tethers are attached between the heart valve and aconnecting ring and placed under tension to maintain the connectionbetween the heart valve, the tethers and the connecting ring, and theconnecting ring provides a convenient and easy way to connect the heartvalve assembly to the distal end of the suture catheter. In someembodiments, the heart valve assembly can be packaged as a pre-assembledunit in a sterile and/or sterilizing solution.

Additional features and advantages will be set forth in part in thedescription that follows, and in part will be obvious from thedescription, or may be learned by practice of the embodiments disclosedherein. The objects and advantages of the embodiments disclosed hereinwill be realized and attained by means of the elements and combinationsparticularly pointed out in the appended claims. It is to be understoodthat both the foregoing brief summary and the following detaileddescription are exemplary and explanatory only and are not restrictiveof the embodiments disclosed herein or as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe various features and concepts of the presentdisclosure, a more particular description of certain subject matter willbe rendered by reference to specific embodiments which are illustratedin the appended drawings. Understanding that these figures depict justsome example embodiments and are not to be considered to be limiting inscope, various embodiments will be described and explained withadditional specificity and detail through the use of the accompanyingdrawings in which:

FIG. 1A schematically illustrates a delivery system that may be used todeliver a replacement heart valve to the mitral annulus;

FIG. 1B provides a schematic representation of a patient's heart andillustrates an exemplary approach for delivering the replacement heartvalve to the mitral annulus using the delivery system of FIG. 1A;

FIG. 2 illustrates a delivery catheter with distal cap configured formaintaining the replacement heart valve in a compressed configurationpre-deployment;

FIG. 3 illustrates an exemplary suture catheter that may be disposedwithin the delivery catheter of FIG. 2 and which is configured forcontrolling axial tension on the replacement heart valve;

FIG. 4 is a perspective view of one embodiment of an artificial heartvalve;

FIG. 5 is a perspective view of an embodiment of a heart valve assembly;

FIG. 6 is a cross-sectional view of the heart valve assembly shown inFIG. 5;

FIG. 7 is a detail view of one of the crests of the heart valve of FIG.4, showing an embodiment of a pin for connecting suture loops to theheart valve;

FIGS. 8A through 8C illustrate side, cross-sectional, and perspectiveviews, respectively, of an embodiment of a connecting ring of the heartvalve assembly;

FIGS. 9A and 9B illustrate cross-sectional and perspective views,respectively, of another embodiment of a connecting ring of the heartvalve assembly;

FIGS. 10A and 10B illustrate cross-sectional and perspective views,respectively, of an embodiment of a suture ring of the heart valveassembly;

FIG. 11 is a cross-sectional view showing the heart valve assemblyconnected to a distal end of an embodiment of a delivery catheter;

FIG. 12 is a cross-sectional view of a distal end portion of anembodiment of a delivery system for the heart valve;

FIG. 13 is a cross-sectional view of an embodiment of a loading funnelused to collapse and load the heart valve into the delivery system;

FIGS. 14 through 16 are cross-sectional views illustrating the heartvalve being loaded directly into the delivery system;

FIG. 17 is a cross-sectional view of an embodiment of a loading toolused to collapse and load the heart valve into a loading funnel;

FIGS. 18 and 19 are cross sectional views illustrating the heart valvebeing loaded into a loading funnel with the use of the loading tool ofFIG. 18;

FIG. 20 is a cross-sectional view of an embodiment of a tensioning toolused to maintain sutures under tension while the collapsed heart valveis transferred from a loading funnel to a delivery system;

FIGS. 21A and 21B illustrate an embodiment of an assembly for loading avalve into the distal end of the delivery system;

FIGS. 22A through 22F illustrate deployment and release of thereplacement heart valve at the mitral annulus.

DETAILED DESCRIPTION Introduction

The present disclosure is directed to devices, systems, and methods forloading, delivering, positioning, and deploying a replacement heartvalve device. Throughout this disclosure, many examples are described inthe context of a replacement artificial mitral valve. One of skill inthe art will understand, however, that the described components,features, and principles may also be utilized in other applications. Forexample, at least some of the embodiments described herein may beutilized for loading, delivering, positioning, and deploying anartificial valve for replacing a pulmonary, aortic, or tricuspid valve.

Moreover, it will be understood that at least some of the deliverysystem embodiments described herein may be utilized in conjunction withother interventional devices, including valve repair devices,annuloplasty devices, clip devices, and other interventional devices notnecessarily configured as a replacement valve. Thus, although thefollowing description will typically refer specifically to a replacementmitral valve device, it will be understood that the same description maybe applied to embodiments which utilize other suitable interventionaldevices in other interventional procedures.

Notwithstanding such alternative applications, preferred embodimentsdescribed herein are configured to address challenges particularlyassociated with loading, delivering, positioning, and deploying anartificial replacement heart valve device. For example, where relativelysimple catheters may be suitable for delivery of a clip or other suchrepair device, the larger size and/or more complex geometry of areplacement valve requires more robust delivery system features toproperly load, deliver, and deploy the device. The embodiments describedbelow are therefore particularly useful in for meeting the additionalprocedural challenges associated with heart valve replacement through anintravascular approach.

Delivery System Overview

FIG. 1A illustrates an embodiment of a delivery system 190. As shown,the delivery system 190 includes a handle assembly 130 and an elongateddelivery member 70 (also referred to herein as simply the elongatedmember or the delivery member). The delivery member 70 is coupled to thehandle assembly 130 and extends distally from the handle assembly 130.The delivery member 70 may include a plurality of catheter and/orhypotube members which provide various functionality during operation ofthe delivery system 190 to enable effective delivery and deployment of areplacement heart valve 10 (shown here in simplified form).

The handle assembly 130 may include one or more controls 134 operativelycoupled to the delivery member to enable steering and/or manipulation ofthe delivery member 70 and/or other components of the delivery system190.

FIG. 1B illustrates a schematic representation of a patient's heart anda delivery procedure that may be conducted using the illustrateddelivery system 190. The delivery member 70 may be inserted into thepatient's vasculature (e.g., through a transfemoral approach) anddirected to the inferior vena cava 150. The delivery member 70 is passedthrough the inferior vena cava 150 toward the heart. Upon entering theheart from the inferior vena cava 150, the delivery member 70 enters theright atrium 152. For replacement mitral valve procedures, the deliverymember 70 must further pass into the left atrium 156 by passing througha puncture in the intra-atrial septum 154.

In other implementations, such as for procedures associated with atricuspid valve, the delivery member 70 may be passed through theinferior vena cava 150 and into the right atrium 152, where it may thenbe positioned and used to perform the procedure related to the tricuspidvalve. As described above, although many of the examples describedherein are directed to mitral valve replacement, one or more embodimentsmay be utilized in other cardiac procedures, including those involvingthe tricuspid valve.

Although a transfemoral approach for accessing a targeted cardiac valveis one preferred method, it will be understood that the embodimentsdescribed herein may also be utilized where alternative approaches areused. For example, embodiments described herein may be utilized in atransjugular approach, transapical approach, or other suitable approachto the targeted anatomy. For procedures related to the mitral valve ortricuspid valve, delivery of the replacement valve or otherinterventional device is preferably carried out from an atrial aspect(i.e., with the distal end of the delivery member 70 positioned withinthe atrium superior to the targeted valve). The illustrated embodimentsare shown from such an atrial aspect. However, it will be understoodthat the interventional device embodiments described herein may also bedelivered from a ventricular aspect. In some embodiments, a guidewire 87is utilized in conjunction with the delivery member 70.

Additional Details of Elongated Member Components

FIG. 2 illustrates one embodiment of a delivery catheter 78 which ishoused and translatable within the outer sheath of the delivery member70. The delivery catheter 78 includes a proximal section 604 and adistal section 602. At the proximal end, the delivery catheter 78includes a seal 606 and an o-ring 608 for forming a fluid tight seal atthe handle assembly 130. In the illustrated embodiment, the distalsection 602 is formed as a compression coil. The compression coilprovides the delivery catheter 78 with ability to effectively push thevalve device through the steering catheter 80 as part of deploying thevalve device. The compression coil also provides good flexibility fornavigating a patient's tortuous vasculature.

The delivery catheter 78 also includes a can structure 610 (i.e.,“distal cap”) disposed at the distal end. The can 610 is configured toconstrain and hold a proximal (i.e., atrial) section of the valvedevice. Without such constraint, the arms of the valve device would bebiased radially outward against the inner surface of the outer sheath,making it more difficult to unsheathe or re-sheathe the valve. The can610 also has a length sufficient to aid in maintaining coaxial alignmentof the distal end of the delivery catheter 78 within the delivery member70 to avoid or minimize unwanted tilting. For example, the can 610preferably has a length to diameter ration of greater than or equal to1, though in alternative embodiments the ratio may be smaller, such asabout 0.25 to 1, depending on the stiffness of the distal section 602.The can 610 also provides an effective structural surface for acting asa counterforce to maintain the valve in position when the outer sheath82 is retracted. In some embodiments, the proximal section of the can610 includes a taper and/or smooth surface for easier sliding of the can610 back into the sheath 82.

FIG. 3 illustrates one embodiment of a suture catheter 72 configured tomaintain axial tension of the valve device prior to deployment. Asexplained in more detail below, the suture catheter 72 is housed withinand translatable within the delivery catheter 78. The suture catheter 72includes a tube section formed as a cut hypotube (e.g., laser cut) toprovide desired flexibility characteristics. A connecting ring 34 isattached at the distal end. The connecting ring 34 includes a tapered,angular surface for more effective advancing through the delivery member70. A series of suture loops 26 are connected to the connecting ring 34.As explained in greater detail below, the suture loops 26 tether tocorresponding attachment points or members of the valve device.

Loading of the Valve Device

FIG. 4 shows one example of a replacement heart valve device that can beintravascularly delivered and deployed using the devices, systems, andmethods disclosed herein. It should be emphasized, however, that thedepicted replacement valve is only one example, and the devices,systems, and methods disclosed herein can be adapted to work with avariety of alternative implantable devices of differing shapes andsizes. In the embodiment illustrated in FIG. 4, valve 10 can beconfigured to self-expand within a cardiac valve orifice, such as themitral annulus, so that the central portion lines the valve orificewhile the atrial and ventricular anchors sit within the chambers of theheart and pinch tissue of the orifice therebetween, securing the valvein place within the heart.

The valve can include an expandable anchor that includes an atrialanchor or ring 12, a ventricular anchor or ring 14, and a centralportion 16 disposed axially between the atrial anchor 12 and theventricular anchor 14. The atrial anchor 12 can be configured to beplaced on, and to engage tissue adjacent to, the atrial side of a mitralannulus. Similarly, the ventricular anchor 14 can be configured to beplaced on, and to engage tissue adjacent to, the ventricular side of amitral annulus. The valve 10 can be formed of a shape-memory alloyadapted to be collapsed into a collapsed delivery configuration (by theapplication of external forces) and biased to return to and expand intoan expanded configuration. The valve 10 can also include a plurality ofstruts secured to at least one of the atrial anchor 12, the ventricularanchor 14, or the central portion 16, the struts being secured to aplurality of replacement leaflets or crests.

The strut frame can be cut from a tubular element, then expanded, andset in the expanded configuration using known shape setting techniques.For example, in an exemplary embodiment, the frame can be cut from a 10mm diameter tube, then expanded to an expanded configuration of about 32mm, and set in the expanded configuration. In some exemplary embodimentsthe strut frames herein are 0.25 mm to about 0.45 mm thick, such asabout 0.35 mm thick. The annular strut frame can be cut from a flatsheet and rolled up and secured together or it can be cut from a tubularstructure.

As further illustrated in FIG. 4, the atrial anchor or ring 12 can beformed from a plurality of atrial leaflets or crests 20 that can beradially spaced about the periphery of the valve 10 and that, in anexpanded configuration, extend proximally and radially outward from aproximal end of the central portion 16. Similarly, the ventricularanchor or ring 14 can also be formed from a plurality of ventricularleaflets or crests 22 that can be radially spaced about the periphery ofthe valve 10 and that, in an expanded configuration, extend distally andradially outward from a distal end of the central portion 16.

As shown in FIGS. 4, 5, and 7, the valve 10 can also include attachmentmembers 24 to which suture loops can be secured. These attachmentmembers 24 can be straight hooks, straight pins, I-connectors, or otherstructures extending from a strut or member of the valve and to which asuture loop can be securely connected during delivery, positioning anddeployment of the valve via a delivery catheter. At the same time,however, the size and configuration of the attachment members 24 shouldalso be selected so as to facilitate a predictable, reliable andcomplete release of the sutures from the valve once the valve has beendeployed and properly positioned within the target location.

In the illustrated embodiment, and as shown in greater detail in FIG. 7,the attachment members can take the form of a pin 24 provided at theapex of each atrial crest 20. Similarly, a pin 24 can be provided insome or all of the ventricular crests 22. In one embodiment, each pin 24can be approximately 0.5 mm to approximately 2.0 mm in length and,preferably, can be approximately 1.0 mm-1.5 mm in length. Each pin 24can also be bent slightly inwards towards a central axis of the valve10.

As illustrated in FIG. 5, a distal end of a suture loop 26 can be passedaround the outside of the atrial crest 20, passed over the end of thepin 24, and then drawn down to the base of the pin 24 by applyingtension to the other, proximal end of the suture loop 26, therebysecuring the distal end of the suture loop 26 between the base of thepin 24 and the inner surfaces of the apex of the atrial crest 20. Withthis configuration, tension on the suture loops 26 applied in a proximaldirection will prevent unintended or inadvertent disconnection orrelease of each suture loop 26 from its associated pin 24. Once thevalve 10 has been properly deployed and positioned within the targetlocation, then release of the valve 10 can be achieved by removingtension on the suture loops 26, which allows the suture loops 26 torelax, detach from the pins 24 and, thereby, disconnect the deliverysystem from the valve 10. Valve 10 may also include a biocompatiblefabric, mesh or other covering (not shown) over some or all of itsexterior surface. If a such a covering is provided, gaps in the coveringaround each pin 24 can be provided so as not to interfere with theattachment of the suture loops 26 to pins 24 during assembly and/orrelease of suture loops 26 from pins 24 following deployment.

It should be appreciated that the process of threading a plurality ofsuture loops 26 around and onto the connecting pins 24 could be arelatively difficult, time consuming and tedious task if attempted inthe lab just prior to a procedure. To provide a more convenient meansfor connecting a plurality of discrete suture loops between the valveand a delivery system, the other end of the suture loops 26 can beconnected to a connecting ring 34, which can be biased to maintaintension on the suture loops 26. The connecting ring can also include afastener or other suitable connection means formed at its proximal endthat can be selectively coupled to a complementary fastener or othersuitable connection means formed at the distal end of the deliverysystem.

Referring to FIGS. 5 and 6, which illustrate a heart valve assembly thatcan be pre-assembled and packaged in a suitable sterile solution, suchas glutaraldehyde, and which also provides a convenient mechanism foreasily attaching the heart valve assembly to a delivery system. In oneembodiment, the heart valve assembly 30 can include valve 10, aplurality of suture loops 26, an elongate shaft or mandrel 32, aconnecting ring 34, a plurality of sacrificial sutures 36, and asacrificial suture ring 38. Elongate shaft 32 extends longitudinallythrough the center of the central portion 16 of valve 10, extendsproximally beyond a proximal end of the valve 10 and extends distallybeyond a distal end of valve 10.

Connecting ring 34 is positioned adjacent and engages a proximal end ofelongate shaft 32. FIGS. 8A through 8C provide detailed views of oneembodiment of connecting ring 34. In the illustrated embodiment, theconnecting ring 34 can include a center lumen 40, a distal shoulderportion 42, and a proximal threaded portion 44. Distal shoulder portion42 includes a plurality of holes 46 spaced radially about the peripherythereof, through which the distal end of suture loops 26 can be securedto connecting ring 34. Connecting ring 34 can also include an annularrecess 45 separating the distal shoulder portion 42 and the proximalthreaded portion 44. Annular recess 45 provides a space for the knotsand loose ends of the sutures loops 26 to reside. As the name implies,threaded portion 44 can include threads which, as discussed inadditional detail below, can engage complementary threads formed in adistal end of a portion of the delivery system to connect the connectingring 34 (and, thus, the heart valve assembly 30) to the delivery system.While the illustrated embodiment shows the use of threads to connect theconnecting ring 34 to the delivery system, any other suitable type ofcomplementary mechanically connection could be adapted and substitutedfor the threaded portions. For example, FIGS. 9A and 9B illustrateanother embodiment of connecting ring 34′ with a mechanical interlock asan alternative to the threaded connection shown in FIGS. 8A-8C. As shownin FIGS. 9A and 9B, connecting ring 34′ can include a plurality ofradially spaced apart extending members. These radially extendingmembers can be configured to engage with a complementary structurewithin the distal end of a portion of the delivery system. For example,the distal end portion of the delivery system can include complementaryslots or recess that receive the radially extending members in afriction fit or other mechanical manner through rotational positioningof the connecting ring relative to the delivery system, or vice versa.

The foregoing are two examples of means for selectively coupling theproximal end of heart valve assembly 30 to a distal end of a deliverysystem. It should be understood, however, that the phrase “means forselectively coupling the proximal end of heart valve assembly 30 to adistal end of a delivery system” is intended to also encompass otherelements, structures and configurations that are known in the art andthat can be substituted and used to perform the same function.

As illustrated in FIG. 6, connecting ring 34 can also include two ormore recesses 47 formed in its distal face that are configured toreceive corresponding pins 48 that can be provided in the proximal endof mandrel 32. The selective coupling of pins 48 within recesses 47fixes the rotational positions of mandrel 32 to connecting ring 34 toone another so that a user can selectively rotate mandrel 32 andconnecting ring 34 together in a clockwise or counterclockwisedirection. Mandrel 32 can also include a centering pin 49 that is sizedto engage the center lumen 40 of connecting ring 34.

Located adjacent the distal end of elongate shaft 32 is a sacrificialsuture ring 38. FIGS. 10A and 10B provide detailed views of oneembodiment of sacrificial suture ring 38. In the illustrated embodiment,sacrificial suture ring 38 can include a center lumen 52 for receivingelongate shaft 32 therethrough. Sacrificial suture ring 38 can alsoinclude an annular flange 54 formed at its proximal end, with aplurality of holes 56 radially spaced about its periphery. Sacrificialsuture ring 38 can also include an annular recess 58 in which sutureknots and ends can be positioned. Sacrificial suture ring 38 can alsoinclude a hole 60 that extends radially outward from the central lumen52, that is threaded, and that is configured to receive a set screw 62therethrough for securing sacrificial suture ring 50 to elongate shaft32. A plurality of sacrificial sutures 36 can be secured between pins 24in the ventricular crests 22 of the valve 10 (see also FIGS. 5 and 6)and the holes 56 provided in the annular flange 54 of sacrificial suturering 50. A desired amount of tension can be applied simultaneously toboth the suture loops 26 and sacrificial sutures 36 by adjusting theposition of sacrificial suture ring 50 along elongate shaft 32. Once thedesired tension is achieved, then the position of the sacrificial suturering 38 can be fixed by advancing set screw 62 into contact withelongate shaft 32, and the applied tension will prevent inadvertent orunintended release or separation of the suture loops 26 from the valve10. Thus assembled, the heart valve assembly 30 can be packaged in asterilized package or container suitable for storage and shipping. Thepackage or container can also include a suitable sterile solution, suchas glutaraldehyde.

While reference is made to use of “sutures” for suture loops 26 andsacrificial sutures 36, it should be understood that any elongate memberthat can provide the functions of the “sutures” described herein couldsubstituted and used in place of sutures. For instance, other elongatemembers can provide a connection between two or more components orstructures and can transmit forces, be tensioned, and be selectivelydisconnected from the two or more components or structures. As such,other materials, such as threads, wires, cords, ribbons, fibers,filaments, strands, cables, etc., or other suitable tensioning elementsor members can be substitute and used in place of sutures.

In addition, while the connection between the distal end of valve 10 andthe sacrificial suture ring 38 in one embodiment can comprise “sutureloops,” other configurations and also be used. For example, as shown inFIG. 6, sacrificial sutures 36 can each also comprise a single strand ofsuture tied at one end to the sacrificial suture ring 38 and fastened atthe other end to a hook that can be selectively connected to and/ordisconnected from the crests 22 of the ventricular ring 14.

Elongate shaft or mandrel 32 can also include a handle 33, similar to ascrewdriver handle or other suitable configuration that can beselectively connected to or integrated as part of the distal end ofshaft 32. Handle 33 can assist in handling and manipulating heart valveassembly 30, particularly while aligning and engaging the threads 44 ofconnecting ring 34 to the threads of the delivery system as described inadditional detail below.

Referring next to FIG. 11, as previously indicated, the proximal end ofconnecting ring 34, and thus the proximal end of heart valve assembly30, can include a threaded portion 44 that is configured to selectivelymate in threaded engagement with a complementary threaded portion of adelivery system. A portion of the distal end of the delivery member 70is graphically represented in FIG. 12, showing the suture catheter 72extending and terminating at a suture catheter tip ring 74. Suturecatheter tip ring 74 can include a threaded portion 76 configured toselectively mate in threaded engagement with threaded portion 44 of theconnecting ring 34 of the heart valve assembly 10 as illustrated. Aspreviously mentioned, other suitable elements, structures andconfigurations can be used, in place of threads, to provide forselective coupling and decoupling between heart valve assembly 30 anddelivery member 70. Due to the force that can be required to collapsethe heart valve from its expanded configuration to a collapsedconfiguration, suture catheter 72 can preferably be made from a hightensile strength material capable of withstanding tension forces of upto 50 pounds (222.4 Newtons).

As graphically illustrated in FIG. 12, the delivery system 70 can alsoinclude other elements or layers that extend from the proximal end tothe distal end. In some embodiments, at least one of the elements of thedelivery system may be located radially and/or co-axially within anouter delivery sheath 82. In one embodiment, delivery system 70 caninclude a suture catheter 72, a delivery catheter 78, a steeringcatheter 80, an outer sheath 82, and/or a valve cover 84 positioned atthe distal end of the outer sheath 82. The delivery system 70 can alsoinclude a guidewire lumen (not shown) positioned within the lumen of thesuture catheter 72 and a guidewire (not shown) positioned within andextending through the lumen of the guidewire lumen. The various layersmaking up delivery system 70 may sometimes be collectively orgenerically referred to herein as “component” layers/members of thedelivery system 70.

Delivery catheter 78 can consist of a stacked coil capable ofselectively delivering a force in the distal direction sufficient todeploy heart valve 10 from valve cover 84. As previously mentioned, toovercome the frictional and other forces that can develop between thecollapsed heart valve 10 and valve cover 84 (due to the resilience andspring force of the shape memory of heart valve 10), in some embodimentsit may be necessary for the stacked coil of delivery catheter 78 todeliver a distal force of up to approximately 50 pounds (222.4 Newtons)in order to cause heart valve 10 to deploy from the distal end of valvecover 84. Delivery catheter 78 can also terminate in a distal end cap orcan 79 (also shown as can 610 in FIG. 2) that engages the proximal endsof heart valve 10.

The delivery system 70 can also include, at its proximal end, a controlfixture (not shown) that attaches to the proximal ends of the variouscomponent layers of the delivery system 70, and which can be used tomanipulate and control movement of the various component layers of thedelivery system 70 relative to one another to perform various functions,including loading the valve 10, navigating the delivery system 70 andvalve 10 through the vasculature to a target location, positioning anddeploying the valve 10 at the target site, and releasing the valve 10from the delivery system 70.

In at least one embodiment, delivery member 70 can also include afriction-reducing layer and/or coating (not shown) on or between one ormore component layers of delivery member 70. For example, afriction-reducing layer and/or coating may include apolytetrafluoroethylene (PTFE) layer positioned on the inner surface ofouter sheath 82 and/or on the outer surface of steering catheter 80. Inother examples, other lubricious coatings, such as perfluoroalkoxy(PFA), fluorinated ethylene propylene, other fluoropolymers, ceramiccoatings, one or more materials combined with a polymer structure (suchas PROPELL available from FOSTER CO.), other materials, or combinationsthereof, may be applied to one or more component layers of deliverymember 70 to reduce friction between the components/elements duringmovement relative to one another. In yet other examples, a hydrophilicor hydrophobic layer may be positioned on or between one or more of thecomponent layers of the delivery member 70.

A replacement heart valve, such as valve 10, may be a self-expandingvalve replacement device with a contracted or collapsed state orconfiguration and an expanded state or configuration. For example, valve10 may be biased toward the expanded state or configuration such thatthe valve cover 84 holds the valve 10 in the contracted or collapsedstate or configuration. By removing the valve 10 from the valve cover 84(i.e., by moving the valve cover 84 in a longitudinal direction relativeto the valve 10, or vice versa), valve 10 can be released from the valvecover 84 and allowed to expand from its contracted or collapsed state orconfiguration toward its expanded state or configuration. In someembodiments, valve 10 may include a shape memory material, such as ashape memory polymer and/or a shape-memory metal, such as a nickeltitanium alloy.

As mentioned above, the heart valve assembly 30 can be preassembled inthe manner described above and packaged in a sterile package orcontainer suitable for transportation and storage. Prior to a procedure,the heart valve assembly 30 can be removed from its packaging orcontainer and rinsed with saline solution. Then, the heart valveassembly 30 can be used to load the valve 10 into delivery member 70.

Reference is next made to FIGS. 13 through 16, which illustrate one wayin which the valve 10 can be collapsed and loaded into the valve cover84 of the delivery member 70. First, FIG. 13 illustrates a loadingfunnel 90 that can be used to facilitate loading of the valve 10 intothe valve cover 84 of delivery member 70. Loading funnel 90 can includea funnel portion 92 located at its distal end and an elongate tubularportion 94 located at its proximal end and communicating with the funnelportion 92. As shown, the funnel portion 92 can preferably be fashionedto smoothly transition from a large diameter at its distal end to asmall diameter at is proximal end. The dimension of the large diameterof the funnel portion can preferably be larger than the outer diameterof the valve 10 in its expanded state, and the dimension of the smalldiameter of the funnel portion can preferably be approximately the sameas the inner diameter of the tubular portion 94. The outer diameter ofthe tubular portion 94 can preferably be slightly smaller than the innerdiameter of the valve cover 84 of the delivery member 70, and thetubular portion 94 can preferably be approximately the same length asthe length of the valve cover 84 of the delivery member 70, such thatthe tubular portion 94 can be selectively inserted into and nest withinthe valve cover 84 of the delivery member 70, as illustrated in FIG. 14.

With the tubular portion 94 of the loading funnel 90 positioned withinthe valve cover 84, controls located on the control fixture (not shown)can be manipulated to cause the suture catheter 72 of the deliverymember 70 to advance in a distal direction relative to the othercomponent layers of the delivery member 70 until the tip ring 74 of thesuture catheter 72 extends distally beyond the distal end of the tubularportion 94 and into the interior of the funnel portion 92, as shown inFIG. 14. Then, as also shown in FIG. 14, the threaded portion 44 ofheart valve assembly 30 can be threaded into the threaded portion 76 ofthe tip ring 74 at the distal end of the suture catheter 72. Appropriatecontrol knobs of the control fixture (not shown) can then be manipulatedto retract the suture catheter 72 in a proximal direction relative toall of the other component layers of the delivery system 72 (and theloading funnel 90). As proximal movement continues, the suture loops 26are drawn into the central lumen of the tubular member 94. This, incombination with the sloping walls of the funnel portion 92, cause theatrial crests 20 of the atrial disc 12 to collapse toward the centralaxis and, eventually, to enter the central lumen of the tubular portion92. Once a sufficient amount of proximally-directed tension is placed onthe suture loops 26 by the suture catheter 72, the sacrificial sutures36 can be cut or otherwise separated from the ventricular ring 14 of thevalve 10, and the elongate shaft 32, and the sacrificial suture ring 38and the sacrificial sutures 36 can be withdrawn from the heart valveassembly 30 and set aside. Further proximal movement of the suturecatheter 72 continues until valve 10 is completely collapsed andcompletely positioned within the tubular portion 94, as illustrated inFIG. 15. Then, the loading funnel 90 can be removed by sliding theloading funnel 90 in a distal direction relative to the delivery member70. By maintaining tension on the suture catheter 72, the valve 10remains stationary as the loading funnel 90 is withdrawn, leaving thefully collapsed valve 10 positioned completely within the valve cover 84of the delivery member 70, as illustrated in FIG. 16.

Reference is next made to FIGS. 17 through 20, which illustrate anotherway in which the valve 10 can be collapsed and loaded into the valvecover 84 of the delivery member 70. Due to the material and structuralproperties of the valve 10, coupled with the relatively large diameterof valve 10 in its expanded state compared to the relatively smalldiameter of the valve cover 84, a relatively large force can be requiredto collapse valve 10 from its expanded state to a collapsed state and/orto draw the valve 10 into the valve cover 84. In some cases, a tensionforce of as much as 40 to 50 pounds (or 177.9 to 222.4 Newtons) may berequired to collapse valve 10 and draw it into valve cover 84. To avoidthe need to provide a delivery system capable of withstanding that muchtension, a separate loading tool can also be provided that is capable ofdeveloping the tension needed to collapse and draw valve 10 into asheath that is approximately the same size as the valve cover 84 andthen transfer the collapsed valve 10 from the loading tool to the valvecover 84 of the delivery member 70.

In this embodiment, the valve 10 is loaded into the loading funnel 90before the valve 10 is connected to the delivery member 70. To do this,a separate loading tool 100 can be provided, which is illustrated inFIG. 17. Loading tool 100 can include an elongate handle 102 with alumen 104 that extends through the longitudinal axis of the handle.Located within lumen 104 is an elongate cylindrical sleeve 106 and anelongate shaft 108. Sleeve 106 and shaft 108 can be sized so that shaft108 closely fits within the lumen of sleeve 106 and yet slides easilywithin sleeve 106. Shaft 108 can include a proximal threaded portion 110on the outside of a portion of its proximal end. Shaft 108 can alsoinclude a distal threaded portion 112 located at its distal end. Thethreads of distal threaded portion 112 are complementary of, and areconfigured to engage the threads of proximal threaded portion 44 of theconnecting ring 34 of the heart valve assembly 30 as discussed inadditional detail below.

Handle 102 also includes a recess 114 that holds a thumbwheel 116.Thumbwheel 116 includes a central threaded bore 118 with threads thatare complementary of the proximal threaded portion 110 of the shaft 108.By rotating thumbwheel 116 about the longitudinal axis of loading tool100, the threads of thumbwheel 116 interact with the threads on shaft108 to selectively advance or retract shaft 108 relative to handle 102,depending on the direction in which thumbwheel 116 is rotated. Loadingtool 100 can also include a quick release feature (not shown) thatallows selective engagement/disengagement of the cooperating threadedportions, as to allow shaft to be quickly advanced and retracted to adesired position relatively handle (and without having to do so rotatingthe thumbwheel 116 alone).

Located at its distal end, the loading tool 100 also includes a hollowcylindrical tube 118 that is concentrically aligned with the centrallumen 104 and that extends in a distal direction from the distal end ofthe handle 102. The inner diameter of the tube 118 can preferably beslightly larger than the outer diameter of the tubular portion 94 of theloading funnel 90, and the length of the tube 116 can preferably beapproximately the same as the length of the tubular portion 94 of theloading funnel 90, such that the tubular portion 94 of the loadingfunnel 90 can be selective inserted into and nest within the tube 118,as illustrated in FIG. 18.

With the loading funnel 90 attached to the distal end of the loadingtool 100, thumbwheel 116 can be rotated to advance shaft 108 in a distaldirection until the distal threaded portion 112 of shaft 108 extendsbeyond the distal end of tube 118 and into the interior of the funnelportion 92, as shown in FIG. 19. Then, as also shown in FIG. 19, thethreaded portion 44 of heart valve assembly 30 can be threaded into thedistal threaded portion 112 of shaft 108 of the loading tool 100. Then,the thumbwheel 116 can rotated in the other direction to cause shaft 108to move in a proximal direction, which causes the suture loops 26 intothe tubular portion 94 of the loading funnel 90. Loading of the valveinto the loading funnel continues in a manner similar to that describedabove, except that the loading handle 100 is used to draw the valve 10into the loading funnel 90 instead of the suture catheter 72 of thedelivery system.

Once the valve 10 is fully collapsed and completely positioned withinthe tubular portion 94 of loading funnel 90, it is then necessary todisconnect connecting ring 34 from shaft 108 of the loading tool 100 andto then connect connecting ring 34 to the suture catheter tip ring 74 ofthe delivery member 70. Before doing so, however, a tensioning tool canbe attached to the loading funnel 90, the tensioning tool beingconfigured to ensure that suture loops 26 are maintained under tensionduring the time the collapsed valve assembly is being transferred fromthe loading tool 100 to the delivery member 70. One embodiment of such atensioning tool 120 is illustrated in FIG. 20. Tensioning tool 120 caninclude a flared portion 122 that is generally complementary in shape tothe interior region of the funnel portion 92 of loading funnel 90. Asillustrated, loading funnel 90 and tensioning tool 120 can includecomplementary fasteners 124 a and 124 b that allow tensioning tool 120to be selectively connected to and disconnected from loading funnel 90.Tensioning tool 120 also includes a spring biased plunger 126 that isbiased in a proximal direction. The distal end of plunger engages a biasspring 128 positioned within a recess formed in the interior of thetensioning tool 120. When tensioning member 120 is attached to loadingfunnel, the force of bias spring 128 biases plunger 126 in a proximaldirection and into engagement with a center portion of the connectingring 34. This proximally-applied force presses against connecting ring34, which places and maintains suture loops 26 under tension.

Once tensioning member 120 has been connected to loading funnel 90(causing tension to be applied to suture loops 26 by spring biasedplunger 126), then thumbwheel 116 can be rotated to cause shaft 108 tomove in a distal direction until the connecting ring 34 emerges beyondthe distal end of tube 118 of loading tool 100. At that point,connecting ring 34 can be disconnected from the distal thread of shaft108 and can then be connected to the threaded portion of the suturecatheter 72 of the delivery member 70 in a manner described above. Then,appropriate controls of the control fixture of delivery member 70 can beactuated to move suture catheter 72 in a proximal direction, therebydrawing the tubular portion (with the collapsed valve 10 containedtherein) into the valve cover 84 of the delivery system. Then, withtension maintained on the suture loops 26 by means of the controlfixture through the suture catheter 72, the loading funnel 90 and thetensioning tool 120 can be removed by sliding them in a distal directionrelative to the valve cover 84.

To help reduce the forces needed to collapse and draw the valve 10through the funnel portion 92 and into the tubular portion 94, onceattached to the suture catheter 72, the heart valve assembly 30 and theloading funnel 90 can be placed in an ice and/or water bath to lower thetemperature of the valve 10 and cause the shape memory alloy to “relax”and become more flexible. In addition, to help collapse the valve 10 ina more radially symmetric configuration, at various times during theloading process the valve 10 can be transferred from the ice/water bathto a warm/hot water bath and then back to the ice/water bath. Thewarm/hot water bath causes the valve 10 to flex as it attempts to returnto expanded shape memory configuration (albeit portions of the valve 10being constrained by the loading funnel 90). This flexing helps thevalve 10 to “self-center” itself within the loading funnel 90 and helpsvalve 10 achieve a more symmetrical, collapsed configuration as loadingcontinues. The valve 10 is then returned to the ice/water bath, andloading continues by continuing proximal movement of the suture catheter72. The process of alternating between an ice/water bath and warm/hotwater bath can be repeated one or more times, as needed, during theoverall loading process.

The process of loading the valve 10 through loading funnel 90 and intovalve cover 84 can be further assisted by providing a support fixturethat combines a container for the ice/water bath and a clampingmechanism that securely holds the distal end of the delivery member 70,including valve cover 84, in a secure and stationary position during theloading process. For example, such a support fixture can include a watertight container capable of holding an ice/water bath in which heartvalve assembly 10, loading funnel 90 and the distal end of deliverymember 70 (i.e., valve cover 84) can be submerged. The support fixturecan also include a clamp secured to the container and located below the“water line” of the ice/water bath. The clamp can be used to selectivelyclamp down on valve cover 84 to secure valve cover 84 in a fixed andstationary position during loading of valve 10 into valve cover 84.

FIGS. 21A and 21B illustrate an embodiment of a supportfixture/container. As illustrated, loading assembly 800 can include areservoir 802 for holding an ice/water bath (other liquid) that canlower the temperature of the tissue valve, and in particular the frameor Nitinol structure, to below its martensite transformationtemperature. By loading the valve when its temperature is below themartensite transformation temperature, the loading process occurs in alow temperature phase in which any plastic or elastic deformationinfluenced by the valve during loading does not affect the finalexpanded deployed state of the tissue valve. In other words, once thetemperature of the valve returns above the martensite transformationtemperature, the valve will transition to the austenite phase and to thedeployed, expanded configuration. In addition, the effect on the Nitinolalso reduces the forces needed to pull in the tissue valve into theouter sheath or valve cover.

As further illustrated, the loading assembly 800 can also include afixture 804 that extends into an interior of the reservoir 802 on oneside and mounts to a base member 806. Fixture 804 can transmit theforces to hold the valve cover to the base member 806 and then to atable or other support 808 that stabilizes the base member 806. Basemember 806 and support 808 could be combined into a single support orstructure for supporting reservoir 802 and one or more of the parts orportions of the loading assembly 800.

Fixture 804 can overlap a portion of reservoir 802 with a lower portion810 submerged in the liquid. Lower portion 810 can be inclined toaccommodate an angular orientation of outer sleeve or sheath or aportion of the elongate member. In another embodiment, lower portion 810need not be inclined, but can be generally parallel to a bottom portionof the reservoir 802 or the base member 806.

Extending from lower portion 810 can be a clamping assembly 812configured to receive and retain the outer sleeve, sheath, or valvecover relative to reservoir 802 and fixture 804. Clamping assembly 812can include two half rings 814 a and 814 b that can be selectivelyconnected by screws or other suitable fasteners. To simplify and speedup the procedure in a cath-lab, clamping assembly 812 can also include aquick engagement/release mechanism. For example, one side of each of thetwo half rings is pivotally mounted together and the other side includesa quick engagement/release lever and mechanism, such as an eccentricclamp or other toggle release. In another embodiment, a single half ringcan be mounted to body 816 of the clamping assembly 812 that has formedtherein a curved portion to receive the outer sleeve, sheath, or valvecover. In another embodiment, clamping assembly 812 can also be disposedoutside of the reservoir 802, but mounted to the base member 806. Ineither embodiment, clamping assembly 812 securely supports and maintainsthe valve cover in a stationary position within the ice/water bath,while allowing axial movement of other component layers of the deliverysystem relative to the valve cover.

As further illustrated, loading assembly 800 can also include a guidingmember 818 that guides the tissue valve into the valve cover or outersheath. Guiding member 818 can be disposed on the end of the valve coveror outer sheath prior to attaching the valve to the delivery system. Inanother embodiment, guiding member 818 could be formed in two piecesthat can be selectively coupled together, which would allow it to beplaced around a portion of the valve cover or outer sheath after theintravascular device is partially attached to the intravascular devicedelivery system, but before it is drawn into or towards the valve coveror outer sheath. In one embodiment, guiding member 818 can be afunnel-shaped C-cone.

Deployment of the Valve Device

FIGS. 22A through 22F schematically illustrate deployment and release ofthe valve 10 at the mitral annulus 158. As shown in FIG. 22A, the distaltip 88 is first advanced relative to the outer sheath 82 and valve cover84 to provide sufficient space for deployment. For clarity, in followingFigures, the tip 88 is not shown. FIG. 22B shows in cross-section thedelivery member in position at the mitral annulus 158, with a distalportion of the valve 10 positioned on the ventricular side, and aproximal portion of the valve 10 positioned on the atrial side. Partialretraction of the outer sheath 82, as shown in FIG. 22C, allows theventricular anchor 14 to release and expand. As shown in FIG. 22D, thevalve 10 may then be retracted proximally to bring the ventricularanchor 14 into firm contract against the mitral annulus 158. This may beaccomplished by retracting the delivery catheter 78. Alternatively, theentire delivery member 70 may be retracted.

As shown by FIG. 22E, the valve cover 84 may then be further retractedto release the atrial anchor 12 on the atrial side of the mitral annulus158. At this point, the valve 10 is still held by the suture loops 26and is not yet fully deployed. This allows the valve 10 to be furtherpositioned or recaptured if necessary. As shown in FIG. 22F, the suturecatheter 72 may then be distally advanced to relieve tension in thesuture loops 26, allowing the atrial anchor 12 to more fully release andexpand. Even further distal advancement of the delivery catheterdetaches the suture loops 26 and allows the delivery member 70 to beremoved from the patient. The longitudinal position of the tip 88relative to the suture catheter 72 can be adjusted as needed while thesuture catheter 72 is advanced. After the valve 10 is detached, the tip88 is retracted and reconnected to the valve cover 84 prior to removalof the delivery member from the patient.

The articles “a,” “an,” and “the” are intended to mean that there areone or more of the elements in the preceding descriptions. The terms“comprising,” “including,” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements. Additionally, it should be understood that references to “oneembodiment” or “an embodiment” of the present disclosure are notintended to be interpreted as excluding the existence of additionalembodiments that also incorporate the recited features. Numbers,percentages, ratios, or other values stated herein are intended toinclude that value, and also other values that are “about” or“approximately” the stated value, as would be appreciated by one ofordinary skill in the art encompassed by embodiments of the presentdisclosure. A stated value should therefore be interpreted broadlyenough to encompass values that are at least close enough to the statedvalue to perform a desired function or achieve a desired result. Thestated values include at least the variation to be expected in asuitable manufacturing or production process, and may include valuesthat deviate by less than 5%, 1%, 0.1%, or 0.01% of a stated value.

Further, elements described in relation to any embodiment depictedand/or described herein may be substituted for or combined with elementsdescribed in relation to any other embodiment depicted and/or describedherein. The present disclosure may be embodied in other specific formswithout departing from its spirit or characteristics. The describedembodiments are to be considered as illustrative and not restrictive.The scope of the disclosure is, therefore, indicated by the appendedclaims rather than by the foregoing description. Changes that comewithin the meaning and range of equivalency of the claims are to beembraced within their scope.

1. A delivery system for intravascularly delivering a replacement heartvalve to a targeted cardiac valve, the delivery system comprising: anexpandable replacement heart valve; a handle assembly; and an elongateddelivery member coupled to the handle assembly and extending distallyfrom the handle assembly, the delivery member having a distal end andbeing configured to detachably couple to the expandable replacementheart valve at the distal end, the delivery member further including: anouter sheath having a valve cover configured to constrain the valve in acompressed configuration; a steering component configured to steer thedelivery member to enable intravascular delivery of the delivery memberto the targeted cardiac valve; a delivery catheter configured tolongitudinally translate the valve relative to the outer sheath; and asuture catheter having one or more tethers configured to detachablycouple to a proximal section of the valve, the suture catheter beinglongitudinally translatable relative to the delivery catheter to enableadjustment of tension in the one or more tethers.
 2. The delivery systemof claim 1, wherein the steering component is a steering catheter nestedwithin the outer sheath.
 3. The delivery system of claim 1, wherein thedelivery catheter includes a distal cap configured in size and shape toconstrain a proximal section of the replacement valve when thereplacement valve is held in the compressed configuration, the distalcap thereby relieving expansion pressure against an inner surface of thevalve cover.
 4. The delivery system of claim 3, wherein the distal caphas a length to diameter ratio sufficient to maintain coaxial alignmentof a distal end of the delivery catheter within the elongated deliverymember.
 5. The delivery system of claim 4, wherein the length todiameter ratio is greater than or equal to
 1. 6. The delivery system ofclaim 3, wherein an outer circumferential wall of the distal cap tapersin thickness from greater thickness proximally to less thicknessdistally.
 7. The delivery system of claim 1, wherein the suture catheteris nested within the delivery catheter.
 8. The delivery system of claim1, wherein the suture catheter includes a connecting ring detachablyconnected to a distal end of the suture catheter, a plurality of tethersbeing coupled to the connecting ring and extending distally from theconnecting ring, each tether connecting to a corresponding attachmentpoint of the replacement heart valve.
 9. The delivery system of claim 8,wherein the suture catheter includes a hypotube section disposedproximal of the connecting ring, the hypotube section including aplurality of cuts for increasing the flexibility of the hypotubesection.
 10. The delivery system of claim 8, wherein the connecting ringincludes a tapered, angular distal surface.
 11. The delivery system ofclaim 8, wherein the connecting ring has a central lumen longitudinallyextending through a center of the connecting ring and a plurality ofholes radially spaced about a periphery of its distal end, the pluralityof tethers being coupled to the plurality of holes.
 12. The deliverysystem of claim 1, wherein the outer sheath includes a friction-reducingcoating on an inner surface of the outer sheath.
 13. The delivery systemof claim 1, wherein the delivery catheter includes a proximal sectionand a distal section, and wherein the distal section is formed as acompression coil.
 14. The delivery system of claim 13, wherein thedelivery catheter is configured to provide a distal force of at leastabout 50 pounds.
 15. A delivery system for intravascularly delivering areplacement mitral valve to the mitral annulus, the delivery systemcomprising: a handle assembly; an expandable replacement heart; and anelongated delivery member coupled to the handle assembly and extendingdistally from the handle assembly, the delivery member having a distalend and being configured to detachably couple to an expandablereplacement heart valve at the distal end, the delivery member furtherincluding: an outer sheath having a valve cover configured to constrainthe valve in a compressed configuration; a steering catheter nestedwithin the outer sheath; a delivery catheter also nested within theouter sheath, the delivery catheter being configured to longitudinallytranslate the valve relative to the outer sheath and relative to thesteering catheter, the delivery catheter including a proximal sectionand a distal section, wherein the distal section of the deliverycatheter is formed as a stacked coil; and a suture catheter nestedwithin the delivery catheter, the suture catheter including a pluralityof tethers extending distally from a distal end of the suture catheter,each tether connecting to a corresponding attachment point of an atrialportion of the replacement valve, the suture catheter beinglongitudinally translatable relative to the delivery catheter to enableadjustment of tension in the tethers.
 16. The delivery system of claim15, wherein the delivery catheter includes a distal cap configured insize and shape to constrain the atrial portion of the replacement valvewhen the replacement valve is held in the compressed configuration, thedistal cap thereby relieving expansion pressure against an inner surfaceof the valve cover.
 17. The delivery system of claim 15, the suturecatheter further comprising a connecting ring detachably connected tothe distal end of the suture catheter, the plurality of tethers beingcoupled to the connecting ring.
 18. A method of deploying a replacementheart valve at a targeted mitral valve, the method comprising: providinga delivery system, the delivery system including an expandablereplacement heart valve, a handle assembly, and an elongated deliverymember coupled to the handle assembly and extending distally from thehandle assembly, the delivery member having a distal end and beingconfigured to detachably couple to the expandable replacement heartvalve at the distal end, the delivery member further including: an outersheath having a valve cover configured to constrain the valve in acompressed configuration; a delivery catheter configured tolongitudinally translate the valve relative to the outer sheath; and asuture catheter having a plurality of tethers configured to detachablycouple to a proximal section of the valve, the suture catheter beinglongitudinally translatable relative to the delivery catheter to enableadjustment of tension in the tethers; intravascularly delivering theelongated delivery member to the targeted mitral valve; retracting theouter sheath relative to the delivery catheter to allow the replacementheart valve to expand, the replacement heart valve being positioned suchthat a distal portion is disposed on a ventricular side of the mitralvalve, a proximal portion is disposed on an atrial side of the mitralvalve, and a central portion is interposed between the distal portionand the proximal portion at the annulus of the mitral valve; andtranslating the suture catheter relative to the delivery catheter tolessen tension in the tethers and allow release of the replacement heartvalve from the elongated delivery member.
 19. The method of claim 18,wherein each one of the plurality of tethers is attachable to acorresponding attachment point at the proximal portion of thereplacement heart valve.
 20. The method of claim 18, wherein the step ofretracting the outer sheath relative to the delivery catheter furthercomprises retracting the outer sheath a first amount to expose theventricular ring of the replacement heart valve, moving the replacementheart valve proximally to bring the ventricular portion into contactwith the ventricular side of the mitral valve annulus, and subsequentlyretracting the outer sheath a second amount to expose the atrial portionof the replacement heart valve.